1. Field of the Invention
The present invention relates to a solid electrolytic capacitor and method for manufacturing the same.
2. Description of Related Art
Development of a solid electrolytic capacitor having small equivalent series resistance (ESR) in a high-frequency range has been recently desired as personal computers (PC) and the like have achieved higher performances.
A solid electrolytic capacitor is formed such that an anode made of a valve metal, such as tantalum or niobium, is anodized to form a dielectric layer mainly of oxide on an anode surface, an electrolyte layer is formed on the dielectric layer, and a cathode layer including a carbon layer and a silver paste layer is formed on the electrolyte layer (for example, see Japanese Patent Application Publication No. Hei 10-321471).
Japanese Unexamined Patent Application Publication No. Hei 3-159222 proposes that, to improve capacitance, tan δ and the like, a mixed layer of a surfactant and graphite is formed or a surfactant layer and a graphite layer are formed on a surface of an electrolyte layer.
However, as a result of the studies carried out by the inventors, it has been found that ESR cannot be sufficiently decreased even if such techniques are used.